Personally I've not tried it myself but we're talking about Peter Gilmore here.

"If you’ve got a slow churn at home you can’t make a pure milk-based ice-cream because it’ll become very icy. At home you’ll normally need at least half cream to the milk, and if you make it more like three-quarters cream you’ll end up with a creamier product in a slow churn. If you use even 50 or 60 per cent cream in these fast professional churns it goes to butter."